1. Field of the Invention
The present invention relates to a simplified dual-frequency antenna for mobile phone, and more particularly to a simplified dual-frequency antenna that has a stop ring with a lower bolt provided at a lower end thereof to enable quick and removable connection of the antenna to a mobile phone by screwing the lower bolt into an antenna jack on the mobile phone.
2. Description of the Related Art
FIGS. 1 and 2 are exploded and assembled perspective views, respectively, of a conventional antenna for mobile phone. The conventional antenna for mobile phone mainly includes two spring coils 10, 20 having large and small coil sizes, respectively, for putting around outer and inner wall surfaces, respectively, of a hollow insulting sleeve 30, and a link 40 connected to a bottom of the sleeve 30. The sleeve 30 is then covered with a protective casing (not shown). Through frequency matching and selection for the two spring coils 10, 20 at outer and inner sides of the insulating sleeve 30, the antenna is adapted to use with a dual-frequency mobile phone.
The spring coils 10, 20 are usually ready-made products. They are manufactured by winding wires around dies and manually adjusting the dies from time to time for the resultant spring coils 10, 20 to meet required specifications, including wire gauge for forming the spring coil, the coil size, the coil spacing, and the length of the coil. It is possible to effectively control such specifications when there is only a small quantity of spring coils to be produced through a die. However, when a large quantity of spring coils 10, 20 are produced, there would be difference in the specifications of the spring coils 10, 20 produced in different batches due to offset or deformation of dies having been used for a long time and some factors that could not be fully overcome in the manufacturing process. Spring coils 10, 20 that do not uniformly meet all the required specifications would inevitably adversely affect the accuracy of the antenna frequency. Moreover, the spring coils 10, 20 tend to compress and tangle with one another and become deformed during packing and transportation. The spring coils are subject to deformed coil spacing when an operator careless pulls the spring coils, making the antenna using these deformed coil springs failed to match the selected frequencies and resulted in poor signal receiving.
The conventional antenna for mobile phone also includes complicate components and requires multiple steps to assemble the antenna and therefore need higher manufacturing costs.
It is therefore a primary object of the present invention to provide a simplified dual-frequency antenna that could be easily protected with a cover and quickly and removably connected to a mobile phone.
To achieve the above and other objects, the simplified dual-frequency antenna for mobile phone of the present invention includes an integrally stamped thin metal conductor to function as a frequency-control structure of the antenna. An upper end of the stamped thin metal conductor is a curved wave coil and a lower end thereof is an elongated contact head. The curved wave coil includes horizontal and vertical wave segments adapted to two different frequencies of 900 MHz and 1800 MHz, respectively. A cover encloses the curved wave coil to protect the coil against impact and deformation. A stop ring with a lower bolt is mounted around a lower portion of the elongated contact head, such that the stop ring is tightly fitted in the cover with the lower bolt exposed from a lower opening of the cover. The lower bolt is adapted to screw into an antenna jack on a mobile phone for a lower end of the elongated contact head to contact with a conductive leaf spring in the mobile phone and for the whole dual-frequency antenna to quickly and removably connect to the mobile phone.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.